Univariate regressions for respiratory impedance (Zrs) variables on height and sex
| Zrs | Coefficient | 95% CI | r2 | p-value | |
| Height | ln R4–16 | −0.714 | −1.060– −0.368 | 0.0070 | <0.001 |
| ln RM | −0.665 | −0.986– −0.344 | 0.070 | <0.001 | |
| 1/FN | 0.070 | 0.042– 0.098 | 0.097 | <0.001 | |
| Sex | ln R4–16 | −0.186 | −0.255– −0.115 | 0.111 | <0.001 |
| ln RM | −0.195 | −0.259– −0.132 | 0.142 | <0.001 | |
| 1/FN | 0.013 | 0.007– 0.0190 | 0.080 | <0.001 |
Zrs variables were normalised for computation of univariate regressions. 95% CI: 95% confidence intervals; ln: natural logarithm; r2: variability of Zrs variables explained by height or sex. R4–16: mean resistance between 4–16 Hz; RM: mean resistance between 4–30 Hz; FN: resonant frequency. n = 223.